1. Field of the Invention
This invention relates to feeding recycled glass, known as cullet, to a glass melting furnace using an adjustable vibrating plate cullet feeder for charging cullet. The cullet feeder of this invention provides independent control of the rate of cullet feed by adjustment of at least one of: the angle of the feeder plate, the intensity of vibration, and the frequency of vibration. The cullet feeder may be adjusted to feed over an existing batch charger or directly into the furnace and controlled by the batch charger or a furnace level or composition controller.
2. Description of Related Art
A number of reciprocating blanket batch chargers are known for feeding glass batch into a melting furnace: U.S. Pat. No. 3,780,889 teaches a reciprocating charger plate which may have its slope changed and may rotate about a vertical axis; U.S. Pat. No. 5,073,183 teaches a hydraulically operated reciprocating batch charger with an adjustable batch gate; U.S. Pat. No. 4,983,206 teaches a reciprocating batch charger with angular adjustment of the plate by jacking the roller assembly; U.S. Pat. No. 5,134,627 teaches a reciprocating batch charger with a pusher bar; U.S. Pat. No. 4,854,959 teaches a reciprocating batch charger with a pusher having a heat seal around the pusher holder and charger; U.S. Pat. No. 4,545,717 teaches a reciprocating batch charger with a movable scraper to seal the slot between the rear wall of the hopper and the charger plate; U.S. Pat. No. 4,226,564 teaches a reciprocating batch charger with a sealing case; U.S. Pat. No. 4,197,109 teaches a reciprocating batch feeder having an enclosure for the feeder and doghouse area.
U.S. Pat. No. 5,158,412 teaches a reciprocating solids charger in which a plurality of jacks adjust the front and rear of a charger plate support upon which the reciprocating drive is fixedly mounted.
U.S. Pat. No. 4,047,920 teaches a batch or cullet feeder which passes the material directly to the top of the melt and distributes the material over the melt surface by rotating pushers. U.S. Pat. No. 5,123,942 teaches a reciprocating batch/cullet charger in which a cullet hopper directly deposits a layer of preheated cullet over a layer of batch on a reciprocating charger plate, the height of the cullet charge being controlled by a gate plate.
Recycling of glass has become important in recent years in the conservation of natural resources and energy. Use of recycled glass, cullet, in high ratios, of 80 weight percent and more, to batch materials has become common in the glass industry, particularly for glass containers. Use of cullet, having different particle size and density as well as different melting characteristics than batch, presents problems requiring careful control of feed of the cullet to the melter for high efficiency results. It is desired to control feed of the cullet separately from the batch and to be able to feed solely cullet to the melter.